At least 91 people, including 20 children, are feared killed by a huge tornado which tore through Oklahoma City suburbs, officials in the US state say.

Worst hit was Moore, south of the city, where neighbourhoods were flattened and schools destroyed by winds of up to 200mph (320km/h).

About 120 people are being treated in hospitals.

President Barack Obama has declared a major disaster in Oklahoma.

He also ordered federal authorities to join in the search efforts which are continuing throughout the night.

Monday's twister hit Moore, a suburb of about 55,000 people, at 14:56 (19:56 GMT) and remained on the ground for about 45 minutes.

The official death toll is 51, but local authorities say the figure is expected to rise as another 40 bodies have been found.
The Oklahoma chief medical examiner's office said at least 20 children were among the dead.

Plaza Towers Elementary school took a direct hit: the storm tore off the building's roof and knocked down walls.

"The school was flattened. The walls were pancaked in," Oklahoma's Lt Gov Todd Lamb told the BBC.

"There's still roughly two dozen children that are missing. There have been some bodies recovered from that school and it's absolutely horrific and devastating."

Another school - Briarwood Elementary - was also damaged, and teachers were later seen leading pupils out to safety.
Oklahoma Gov Mary Fallin said it was a "tragic" day.

More than 200 Oklahoma National Guardsmen as well as out-of-state personnel have been called in to assist the search-and-rescue effort.

The BBC's Alastair Leithead in Oklahoma says many of tornadoes in the region hit the open plain, but this one struck a residential area.

Many houses are built on hard ground without basements, so many people did not have recourse to shelter, our correspondent adds.

"We locked the cellar door once we saw it coming, it got louder and next thing you know is you see the latch coming undone," survivor Ricky Stover said.

"We couldn't reach for it and it ripped open the door and just glass and debris started slamming on us and we thought we were dead, to be honest."

Melissa Newton said: "There's shingles and pieces of sheet rock and wood in our yard and all across our neighbourhood. Some homes are completely gone. It's devastating."

James Rushing said he had hurried to Plaza Towers Elementary School, where his foster son Aiden was a pupil, to see it destroyed by the storm.

"About two minutes after I got there, the school started coming apart," he told the Associated Press news agency.
The National Weather Service (NWS) said Monday's tornado had generated winds of up to 200mph.

"It's certainly the most powerful tornado that I've ever dealt with in my 20 years with the weather service," NWS meteorologist Rick Smith in Norman, Oklahoma, told the BBC.

The town of Moore was hit by a severe tornado in May 1999, which had the highest winds ever recorded on Earth.
But Betsy Randolph of the Oklahoma Highway Patrol told local news station Skynews 9 that the damage on Monday appeared to exceed that of the 1999 tornado.

Tornadoes, hail and high winds also hit Iowa and Kansas, part of a storm system stretching from Texas to Minnesota.
On Sunday, a tornado smashed a trailer park on Highway 102 near Shawnee, Oklahoma.

Oklahoma's state medical examiner confirmed earlier on Monday that two people had been killed in the area.

I remember, at age five, having a layover (flight) in Texas, and they had a tornado warning... and I was scared to death. My aunt "cheered" me up by reminding me that I live in California, where there are no "warnings" for earthquakes; earthquakes just heroine, and they are ten times more destructive that tornados.

I didn't sleep for months.

Whenever I hear about tornados, I think of earthquakes, and thus I also think, " Fuck you, aunt!!!"

Let's hope there are more stories like this coming out of Moore, Okla., where people continue to pick through the rubble of their town for family, friends and pets who managed to survive the storm. In the video below you'll meet Barbara Garcia, an elderly woman who rode out the storm by taking refuge in the bathroom of her since-destroyed home. Things get good—and may just get a little dusty in your office—at about the 1:35-mark when she discovers her missing dog Toto, shaken but seemingly largely uninjured, in the rubble. "Well I got God to answer one prayer to let me be OK, but he answered both of them because this was my second prayer," Garcia says, partly to the camera and partly to herself.

WASHINGTON -- As frantic rescue missions continued Monday in Oklahoma following the catastrophic tornadoes that ripped through the state, it appeared increasingly likely that residents who lost homes and businesses would turn to the federal government for emergency disaster aid. That could put the state's two Republican senators in an awkward position.

Sens. Jim Inhofe and Tom Coburn, both Republicans, are fiscal hawks who have repeatedly voted against funding disaster aid for other parts of the country. They also have opposed increased funding for the Federal Emergency Management Agency (FEMA), which administers federal disaster relief.

Late last year, Inhofe and Coburn both backed a plan to slash disaster relief to victims of Hurricane Sandy. In a December press release, Coburn complained that the Sandy Relief bill contained "wasteful spending," and identified a series of items he objected to, including "$12.9 billion for future disaster mitigation activities and studies."

Coburn spokesman John Hart on Monday evening confirmed that the senator will seek to ensure that any additional funding for tornado disaster relief in Oklahoma be offset by cuts to federal spending elsewhere in the budget. "That's always been his position [to offset disaster aid]," Hart said. "He supported offsets to the bill funding the OKC bombing recovery effort." Those offsets were achieved in 1995 by tapping federal funds that had not yet been appropriated.

In 2011, both senators opposed legislation that would have granted necessary funding for FEMA when the agency was set to run out of money. Sending the funds to FEMA would have been "unconscionable," Coburn said at the time.

Hart said Coburn had "never made parochial calculations" about Oklahoma's disproportionate share of disaster funds, "as his voting record and campaign against earmarks demonstrates." Hart added that Coburn, "makes no apologies for voting against disaster aid bills that are often poorly conceived and used to finance priorities that have little to do with disasters."

A representative for Inhofe could not immediately be reached for comment. Inhofe earlier tweeted: "The devastation in Oklahoma is heartbreaking. Please join me and #PrayforOklahoma. Spread the word."

Coburn also put out a message on Twitter, writing, "My thoughts and prayers are with those in Oklahoma affected by the tragic tornado outbreak."

Oklahoma currently ranks third in the nation after Texas and California in terms of total federal disaster and fire declarations, which kickstart the federal emergency relief funding process. Just last month, President Barack Obama signed a disaster declaration for the state following severe snowstorms.

And despite their voting record on disaster aid for other states, both Coburn and Inhofe appear to sing a different tune when it comes to such funding for Oklahoma.

In January of 2007, Coburn urged federal officials to speed disaster relief aid after the state faced a major ice storm.

A year later, in 2008, Inhofe lauded the fact that emergency relief from the Department of Housing and Urban Development would be given to 24 Oklahoma counties. "The impact of severe weather has been truly devastating to many Oklahoma communities across the state. I am pleased that the people whose lives have been affected by disastrous weather are getting much-needed federal assistance," he said at the time.

The cost of the recovery effort for this week's tornadoes is likely to be high. After a spate of tornadoes in the state in 1999, Oklahomans requested and received $67.8 million in federal relief funds.

The people in Moore need help quickly. Let's hope the relief isn't delayed this time.